Flat bed sewing machine



March 10, 1970 G. M. REIMER 3,499,407

FLAT BED SEWING MACHINE 5 Sheets-Sheet 1 Filed sept. 19, 1967 .f I j March 10, 1970 G. M. REIMER 3,499,407

FLAT BED .SEWING MACHINE Filed Sept. 19, 1967 s sheets-sheet z 2b 37 HG2.

March 10, 1970 G. M. REIMER 3,499,407

FLAT BED SEWING MACHINE Filed Sept. 19, 1967 3 Shee1...-Sheel'l 5 United States Patent O U.S. c1. 112-218 s claims ABSTRACT F THE DISCLOSURE A sewing machine having a needle bar, looper and feed bars in which the drive connections between the drive, the needle bar, looper and feed bars are resiliently mounted in the sewing machine frame by resilient pivots and supports, such resilient pivots and supports having a Shore Scale A durometer not substantially lower than 80 and not substantially higher than 90. v

This application is a continuation-in-part of application Ser. No. 416,500, filed Dec. 7, 1964, now abandoned, and relates to sewing machines and, more particularly, to high speed sewing machines.

One difficulty encountered in increasing the speed of sewing machines is the noise created by the increase in machine speed. In addition to normal, low-level noises or sounds usually encountered and expected, increasing the machine speed usually results in high-pitched noises or sounds which, when combined with the normal, lowlevel sounds, are annoying and fatiguing to the machine operator and creates uncomfortable conditions, especially when a number of machines are operated simultaneously in a battery. The principal source of such high-pitched or high-frequency sounds is in the needle drive system. These sounds depend, to a certain extent, on the travel of the needle and needlebar, and may reach levels of 98 to 100 decibels. The longer the travel of the needle and needle bar, the higher the decibel reading and, conversely, the shorter the travel, the lower the reading. Other sound sources are the feed bar and looper drives.

While some sounds are not bothersome and can be tolerated, certain sounds, especially those at relative high frequency, are particularly annoying and fatiguing. Thus, many of the advantages `attained by increasing machine speeds are lost by increases in annoyancesto, and fatigue of, the machine operator.

The instant invention is directed, primarily, to this noise problem and is of particular advantage-when incorporated in sewing machines designed for operation at speeds of 5500 r.p.rn. or stitches per minute and higher speeds. For purposes of convenience such sewing machines yare hereinafter referred to as high-speed sewing machines.

One of the objects of the instant invention is to provide an improved high-speed sewing machine.

A further object of the invention is to decrease the noise level, particularly the high-pitched and high-frequency noise level, of such sewing machines.

A still further object of the invention is to provide such an improved sewing machine with a minimum of alterations to the machine mechanism and without sacrifice in the functions of the machine.

These and other objects will be more apparent from the following description and the attached drawings in which:

FIG. 1 is a side elevational view, in section, of a machine embodying the instant invention;

FIG. 2 is a top plan view, partly in section and in an 3,499,407 Patented Mar. 10, 1970 ICC enlarged scale, of the base of the machine, with some parts removed;

FIG. 3 is a front elevational view, partly in section, of the machine of FIG. 1;

FIG. 4 is an enlarged view, in section, taken along the line 4 4 of FIG. 1;

FIG. 5 is an enlarged view of the resilient bushing of the instant invention; and

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5.

The instant invention is illustrated on a tlat bed sewing machine employing the usual needle bar, looper and feed bar. In such a machine, the needle bar, looper and feed bar are driven from a rotatable shaft by members supported for limited pivotal motion about pivots mounted in fixed position on the machine housing. It is to be understood that the instant invention is not limited to this type of machine but may be used in any sewing machine where a pivoted member is employed to move or drive parts of the machine with controlled movement. The instant invention may also be employed in the drive of other sewing machine parts where such drive is through a pivoted member mounted for pivotal movement on the machine housing. Only those parts pertinent to an understanding of the invention will be described.

Referring now to the drawings, especially FIGS. 1, 2 and 3, the illustrated sewing machine has a work-supporting base 2, a vertical standard 4, an overhanging arm 6, and a needle head 8. Work-supporting base 2, vertical standard 4, overhanging arm `6, and needle head 8, may be a single housing, as the single casting illustrated, or may be separate housings bolted or otherwise suitably fastened together.

The machine is driven through shaft 10. Pulley 12 is keyed to one end of shaft 10 and is connected by a belt to a power source, not shown. Fly-wheel 14, which also serves, in the conventional manner, as a handwheel for manual turning of the machine, is fastened to pulley 12. Shaft 10 is provided with couplings 10a and 10b for purposes of assembly and servicing.

`Needle bar 16 is mounted in frame 18 of needle head 8 for vertical movement relative to work-supporting base 2 and is connected, by link 20, to one end of needle lever 22, pivotally supported on pivot shaft 24 mounted in fixed, stationary position on bosses `6a and 6b of overhanging arm 6 (see FIG. 4). Shaft 24 is held in fixed position in the bosses by set screws 24a, 24b, which extend through the bosses into the shaft. Resilient O-ring 23, 25, at the opposite ends of shaft 24, form oil-tight seals between overhanging arm 6 and shaft 24. A resilient bushing, sometimes herein referred to as needle lever bushing, having an outer metal sleeve 27, an inner metal sleeve 29, and an intermediate resilient member 31, is positioned in lever 22 intermediate the lever and shaft 24. At its end opposite needle bar 1'6, needle lever 22 is connected, by lball pin 26, to one end of pitman 28, the opposite end of pitman 28 being connected vto the crank portion 30 of shaft 10.

, Referring still to FIGS. 1, 2 and 3, feed bar 32 is supported, at one of its endsJfor limited vertical movement toward and away from the needle by mechanism similar to that shown in U.S. Patent 2,884,883 and, at its opposite end, is pivotally connected, by hollow shaft 34, to one end of feed rocker 36. Feed rocker 36 is pivotally supported, at its opposite end, to rocker shaft 38. Rocker shaft 38 is mounted, for pivotal movement on work-supporting base 2, in bosses 20:, 2b, fixed to work-supporting base 2. Intermediate' each boss 2a, 2b, and rocker shaft 38 is a resilient bushing, hereinafter sometimes referred to as rocker bushing, having an outer metal sleeve 37, an

inner metal sleeve 39, and an intermediate resilient member41.

A trunnion or stud 40 is connected to feed rocker 36 intermediate the ends of the feed rocker and, as best shown in FIG. 2, extends outward from the feed rocker. At its forward end trunnion 40 is connected, by clamping screw 42, to one end of arm 44. Arm 44 is connected, at its opposite end, by pin 46, to pitman 48 which, in turn, is connected to disc 54 through crank pin S0 carried in slot 52. Disc 54 is secured to the end of shaft 10.

Referring now to FIG. 3, presser foot 56 is fastened to one end of presser bar 57. Presser bar 57 is mounted for vertical movement in needle head 8 by bearing S8. At its opposite end, presser bar 57 extends into one end of coil spring 60, the opposite end of coil spring 60 receiving one end of pin `62 threaded in needle head 8. At its opposite end, pin 62 is provided with knurled knob 64. Rotation of knurled knob 64 regulates the tension of coil spring 60 and the pressure on the presser foot.

Turning again to FIGS. 1 and 2, looper y66 is connected to one end of looper rocker 68, the rocker being pivoted, at its opposite end, on cone stud 69 of screw stud 70 fixed to sleeve 72. Sleeve 72 is carried on rock shaft 76 mounted, at its opposite ends, for rocking motion in worksupporting base 2.

Rotary shaft is provided with a spherical crank 78. Pitman 80 is connected, at one of its ends, to spherical crank 78 and at its opposite end, to ball pin 82 of looper drive arm 84. At its opposite end, arm 84 is locked to shaft 86 which, at its opposite ends, is mounted for rocking movement in work-supporting base 2 at bosses 2c, 2d, by resilient bushings, sometimes referred to herein as looper drive arrn bushing, having inner and outer metal sleeves 85, 87 and an intermediate resilient member 89. Looper drive level 8 is clamped, at one of its ends, to the end of shaft 86 and, at its opposite end, is connected to one end of link 90. At its opposite end, link 90 is connected to the mechanism of looper 66.

In the machine described, the resilient bushing of the instant invention is employed in three locations, namely, between needle lever 22 and shaft 24, between rocker shaft 38 and bosses 2a and 2b of work-supporting base 2, and between rocker shaft 86 and bosses 2c and 2d of work-supporting base 2. Except for differences in dimension to accommodate the different shafts, bosses, levers, and the like, the resilient bushings are, for present purposes, identical. Thus, the description which follows, while directed to the resilient bushing intermediate needle lever 22 and shaft 24, illustrated in enlarged detail in FIGS. 5 and 6, is also applicable to the other resilient bushings.

The bushings of lFIGS. 5 and 6 include an outer member 27 of metal and an inner member 29 of metal. Outer metal member 27 may be fabricated from steel or other suitable metal. The inner metal member is preferably formed from metal bearing material, such as, bronze, brass, or the like, and is provided with a groove 29a extending helically along the inside surface of inner member 29 from one end of the inner surface to the opposite. Inner member 29 is slightly longer than outer member 27 and projects, at its ends, slightly beyond the ends of the bushing. These projecting ends serve as a spacer between the ends of the bushing and the housing (see FIG. 4), and are provided, at their ends, with slots 29b which extend through the inner member 29. Slots 29b and groove 29a permit flow of lubricant between the inner wall of inner member 29 and the supported member. Flow of lubricant through groove 29a provides necessary lubricant and, in addition, assists in cooling.

A resilient member 31, of oil and heat resistant rubber, synthetic rubber, or resilient vulcanizable plastic, is positioned intermediate inner and outer members 27, 29. The durometer, or hardness, of the resilient member of the bushing of the instant invention is critical. Where the ,g 4 durometer, measured on Scale A of a Shore durometer, is substantially less than 80, in sufficient support for the pivoted member results and overthrow occurs in the drive. On the other hand, when the durometer, or hardness, of the resilient member, measured on Scale A of a Shore durometer, is substantially more than 90, the noise level of the machine is not substantially reduced. A Shore Scale A durometer of is preferred.

The bushing of the instant invention is preferably formed by assembling inner and outer members 27, 29, with the uncured or unvulcanized resilient material in place. While maintaining the resilient material under pressure, the resilient material is then vulcanized, or cured, in situ between members 27, 29. A bonding agent between the contacting surfaces of members 27 and 29 and resilient member 31 may be employed and is preferred. l Y

The terms and expressions which have been employed are used as terms of descriptions and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible.

What is claimed is:

1. In a sewing machine having a hollow frame comprising, a work-supporting member, a vertical standard, an overhanging arm carrying a needle head at its end, a reciprocable needle bar in said head, a looper, a feed bar, and a rotary shaft for driving said needle bar, said looper and said feed bar, a needle lever in said' overhanging arm, means at one end of said needle lever for connecting said needle lever to said needle bar, means at the opposite end of said needle lever for connecting said needle lever to said rotary shaft, pivot means intermediate the opposite ends of said needle lever for supporting said lever for pivotal movement in said overhanging arm, said pivot means comprising a pivot shaft mounted in said overhanging arm and passing through said needle bar, a resilient needle lever bushing on said pivot shaft intermediate said needle lever and said pivot shaft for resiliently mounting said needle lever for pivotal movement on said pivot shaft, means interconnecting said rotary shaft and said looper including a looper drive shaft pivotally mounted on said work-supporting member, a looper drive shaft resilient bushing intermediate said looper drive shaft and said Work-supporting member for resiliently supporting said looper drive shaft for pivotal movement on said Work-supporting member, and means interconnecting said rotary `shaft and said feed bar including a rocker pivotally mounted on said work-supporting member and a resilient rocker bushing intermediate said rocker and said worksupporting member for resiliently supporting said rocker for pivotal movement on saidY work-supporting member, said needle lever bushing, said looper drive shaft bushing and said rocker bushing each having an inner metal member, and an outer metal member and an oil resistant, vulcanized, synthetic rubber having a Shore Scale A durometer of not lower than 8O and not higher than 90 intermediate said inner member and said outer member, said inner metal member having a spiral groove extending from one end of said inner metal member to the other end thereof along the inner surface of said inner metal member. i

2. In a sewing machine as recited in claim 1 in which the Shore Scale A durometer of said resilient member is 85.

3. In a sewing machine having a hollow frame and comprising, a work-supporting member, a vertical standard and an overhanging arm carrying a needle head at its end, a reciprocable needle lbar in said head carrying a needle, and a rotary shaft for driving said needle bar, a needle lever vin said overhanging arm, means at one end of said needle lever for connecting said needle lever to said needle bar, means at the opposite end of saidv lever for connecting said needle lever to said rotary shaft and resilient pivot means intermediate the opposite ends of said needle bar for resiliently supporting said needle lever for pivotal movement in said overhanging arm, said pivot means comprising a shaft mounted at its opposite ends in said overhanging arm, said shaft, intermediate its ends, passing through said needle lever and a resilient bushing intermediate said shaft and said needle lever, said resilient bushing supporting said needle lever for pivotal movement on said shaft, said resilient bushing having an inner metal member, an outer metal member and an intermedi-V ate resilient vulcanized, oil resistant, synthetic rubber member having a Shore Scale A durometer of not less 80 and not more than 90 intermediate said metal members, said inner metal member having a spiral groove extending along the inner surface of said inner metal member from one end of Said inner metal member to the opposite end thereof, said groove forming, with said shaft passing therethrough, a passageway for a lubricant between said resilient bushing and said shaft.

4. In a sewing machine as recited in claim 3 in which the Shore Scale A durometer of said resilient member is 85.

5. In a sewing machine having a hollow frame comprising, a work-supporting member, a vertical standard and an overhanging arm carrying a needle head at its end, a reciprocable needle bar in said head carrying a needle, a looper, and a rotary shaft for drivin-g said needle bar and said looper, means interconnecting said rotary shaft and said looper including a looper drive shaft pivotally mounted on said work-supporting member, and resilient means intermediate said looper drive shaft and said worksupporting member for resiliently supporting said looper drive shaft for pivotal movement on said work-supporting member, said resilient means having an inner metal member, an outer metal member and an oil resistant, vulcanized, synthetic rubber member having a Shore Scale A durometer of not less than 80 and not more than 90 intermediate said metal members, said inner metal member having a groove extending along its inner surface from one end of said inner metal member to the opposite end thereof, said groove with said looper drive shaft forming a passageway for lubricant between said inner metal member and said looper drive shaft 6. In a sewing machine as recited in claim 5 in which the Shore Scale A durometer of said resilient member is 85.

7. In a sewing machine having a hollow frame comprising, a work-supporting member, a vertical standard and an overhanging arm carrying a needle head at its end, a reciprocable needle bar in said head, a feed bar, and a rotary shaft for driving said needle bar and said feed bar, means interconnecting said rotary shaft and said feed bar including a rocker pivotally mounted on said work-supporting member, and resilient means intermediate said rocker andy said work-supporting member for resiliently supporting said rocker for pivotal movement on said work-supporting member, said resilient means having an inner metal member, an outer metal member and a resilient, vulcanized, oil resistant, synthetic rubber member having a Shore Scale A durometer of not less than and not more than 9() intermediate said metal members, said inner metal member having a spiral groove extending along its inner surface from one end thereof to the opposite end, said spiral groove forming a passage for lubricant.

8. In a sewing machine as recited in claim 7 in which the Shore Scale A durometer of said resilient member is 85.

References Cited UNITED STATES PATENTS 1,510,804 10/1924 Sherwood 308-26 XR 1,758,712 5/1930 Morris 308-26 XR 2,057,507 10/1936 Weidenbacker 308-26 XR 2,792,797 5/1957 Hayes et al.

2,884,883 5/1959 Reimer 112-200 XR 3,000,657 9/1961 Boschi et al 308-26 XR 3,171,699 3/1965 Maxey 308-26 3,202,458 8/1965 Domes 308-26 XR 3,239,286 3/1966 HarrisOn 308-26 H. HAMPTON HUNTER, Primary Examiner U.S. Cl. X.R. 308-26 

